1. Field of the Invention
This invention relates to gravity-powered electrical energy generators and, in particular, to apparatus adapted for providing light without the necessity of using electrical storage devices.
2. Description of the Related Art
Since the dawn of civilisation, people have desired light during the hours of darkness. For the majority of prehistoric and historic times, this has been provided by combustion of an appropriate fuel, originally a fire using whatever combustible material was to hand and later using a combustible hydrocarbon fuel, for example wax in the case of candles and tapers or, more recently, various oils. The modern development of the oil and gas industry has led to the development of lamps fuelled by kerosene or paraffin, or by a cylinder of compressed gas, usually, though not exclusively, butane. Such lighting consumes fossil fuels and is accordingly environmentally damaging and ultimately unsustainable.
The development of the electric light bulb during the 19th century enabled a vast increase in the amount of night time lighting to be achieved, albeit at the substantial capital cost of installing the necessary grid infrastructure to distribute electricity, as well as the investment needed in electrical generation plant, whether by burning fossil fuel or latterly by hydroelectric power. While electrical lighting became ubiquitous in the industrially developed countries, it has never been a solution to the problem of providing light at night in rural areas and in developing countries.
During the 20th century, major advances were made in terms of the efficiency of light generation from electrical devices, as well as in the development of electrical storage systems, albeit that the latter generally involve the construction of electrical storage cells using expensive materials which are often
toxic and which in turn gives rise to disposal problems, particularly in the case of non-rechargeable storage devices.
The 20th century also saw the development of devices and materials able to convert sunlight direct to electricity, so enabling a ‘solar panel’ to collect light and produce electricity during the day and feed it to a storage device, whence the stored electrical power could be tapped during the night to operate a light. Again, the investment required to manufacture solar panels is substantial, and they are prone to damage unless substantial steps are taken to preserve them. They also have a limited service life and, despite recent increases in efficiency, simply do not produce that much power.
Attempts have been made in the past to provide apparatus for converting the power of gravity acting on a weight to electrical power. U.S. Pat. No. 5,905,312 describes a gravity-powered electrical generation system which is powered by water which is fed from a tank above the apparatus into a series of small tanks which are mounted on a vertical loop of material. The weight of water in the tanks causes the loop to turn and its slow rotation is converted via a system of gearing into fast rotation of the power input shaft of an electrical generator. Such a device is complex to build and maintain and unsuited for generating small quantities of electricity to produce light in rural areas.
A columnar light powered by gravity was announced in February 2008. It was said to be the idea of Clay Moulton and disclosed generating electricity by the slow fall of a mass which spins a rotor. The energy thereby released was said to power ten high output LEDs which emitted light into an acrylic lens to create a diffuse light. The device was described as requiring the turning over of an hourglass-like mechanism to move a movable weight from a lower position to a higher position, whereafter it would glide gently downwards while lighting the lamps.